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1: Respirology (Carlton, Vic.), 2010 Mar 19,
CCL22 is involved in the recruitment of CD4CD25 T cells into tuberculous pleural effusions.

[Abstract]ABSTRACT Background and Objective: CD4(+)CD25(high) regulatory T cells are increased in tuberculous pleural effusions (TPE). However, the mechanism by which CD4(+)CD25(high) T cells infiltrate into the pleural cavity is unknown. The aim of this study was to investigate whether the chemokines CCL22 and CCL17 are present in TPE, and the chemoattractant activity of these chemokines for infiltration of CD4(+)CD25(high) T cells into the pleural space. Methods: The concentrations of CCL22 and CCL17 were measured in pleural effusions from 33 patients with tuberculous pleurisy, 21 patients with pleural bacterial infections and 18 patients with transudative pleural effusions. T lymphocyte subsets in pleural effusions were assessed by flow cytometry. Pleural effusion cells were analysed for the expression of CCL22. The chemoattractant activity of CCL22 for CD4(+)CD25(high) T cells was assessed in vitro. Results: The frequency of CD4(+)CD25(high) T cells was significantly higher in TPE than in blood. High concentrations of CCL22 were detected in tuberculous effusions, but not in bacterial effusions or transudates. Macrophages and T cells in TPE expressed CCL22. Tuberculous pleural fluid was chemotactic for CD4(+)CD25(high) T cells in vitro, and anti-CCL22 antibody partly inhibited this chemotactic activity. Conclusions: CCL22 appeared to be increased in TPE compared with bacterial pleural effusions or transudates. CCL22 may be responsible for the infiltration of CD4(+)CD25(high) T cells into the pleural space of patients with tuberculous pleurisy.

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2: International journal of cancer. Journal international du cancer, 2010 Mar 2,
NK depletion results in increased CCL22 secretion and treg levels in lewis lung carcinoma via the accumulation of CCL22-secreting CD11b(+)CD11c(+) cells.

[Abstract]Tumor induced immune suppression involves the accumulation of suppressive infiltrates in the tumor microenvironment such as regulatory T-cells (Tregs). Previous studies demonstrated that NK-dependant increases in CCL22 secretion selectively recruit Tregs toward murine lungs bearing Lewis Lung Carcinoma (LLC). In order to extend the in vitro studies, the present studies utilized in vivo depletion of NK cells to ascertain the contribution of NK-derived CCL22 toward total CCL22 and subsequent Treg levels in both normal and LLC-bearing lungs. However, NK depletion had the unexpected effect of increasing both CCL22 secretion and Treg levels in the lungs of NK-depleted LLC-bearing mice. This was concurrent with an increase in tumor burden. Flow cytometry and a series of both immunomagnetic and FACS isolations were used to identify the CCL22-producing cellular fractions in LLC-bearing lungs. A novel CD11b(+)CD11c(+) cell population was identified that accumulates in large numbers in NK-depleted LLC-bearing lung tissue. These CD11b(+)CD11c(+) cells secreted large amounts of CCL22 that may overcompensate for the loss of NK-derived CCL22 in the lungs of NK-depleted LLC-bearing mice. Taken together these data suggest that NK cells play both a positive and negative role in the regulation of CCL22 secretion and, in turn, the recruitment of Tregs toward LLC-bearing lungs. (c) 2010 UICC.

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3: Diseases of the esophagus : official journal of the International Society for Diseases of the Esophagus / I.S.D.E, 2009 Dec 14, 92(2)
CCL17 and CCL22 chemokines within tumor microenvironment are related to infiltration of regulatory T cells in esophageal squamous cell carcinoma.

[Abstract]It has been reported that an increased population of regulatory T cells (T-regs) is one of the reasons for impaired anti-tumor immunity. We investigated the frequency of Foxp3(+) T-regs in tumor-infiltrating lymphocytes (TILs) and peripheral blood lymphocytes (PBLs) of patients with esophageal squamous cell carcinoma (ESCC). Furthermore, in order to elucidate the mechanisms behind T-regs accumulation within tumors, we evaluated the relationship between CCL17 or CCL22 expression and the frequency of Foxp3(+) T-regs. CD4(+)CD25(+)Foxp3(+) T-regs as a percentage of CD4(+) cells were counted by flow cytometry. The frequency of CCL17(+) or CCL22(+) cells among CD14(+) cells in tumors was also evaluated by flow cytometry. Moreover, an in vitro migration assay using T-regs derived from ESCC was performed in the presence of CCL17 or CCL22. The frequency of Foxp3(+) T-regs in TILs was significantly higher than that in the normal esophageal mucosa (24.6 +/- 10.0 vs 7.1 +/- 5.9%, P < 0.01). The frequency of Foxp3(+) T-regs in PBLs of ESCC patients was significantly higher than that in normal healthy donors (7.0 +/- 4.2 vs 2.5 +/- 1.0%, P < 0.01). Furthermore, the frequency of CCL17(+) or CCL22(+) cells among CD14(+) cells within tumors was significantly higher than that of normal esophageal mucosa, and there was a significant correlation between the frequency of CCL17(+) or CCL22(+) cells and Foxp3(+) T-regs in TILs. In addition, the in vitro migration assay indicated that T-regs were significantly induced to migrate by CCL17 or CCL22. In conclusion, CCL17 and CCL22 within the tumor are related to the increased population of Foxp3(+) T-regs in ESCC.

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4: British journal of pharmacology, 2009 Aug, 157(8)
Fluvastatin inhibits expression of the chemokine MDC/CCL22 induced by interferon-gamma in HaCaT cells, a human keratinocyte cell line.

[Abstract]BACKGROUND AND PURPOSE: The macrophage-derived chemokine (MDC/CCL22) is a prototypic Th2-type chemokine intimately involved in Th2-skewed allergic diseases, such as atopic dermatitis and asthma. The statins (3-hydroxy-3-methyl glutaryl coenzyme A reductase inhibitors) have been demonstrated to relieve allergic inflammation. However, the immunological effects and mechanisms of statins against atopic dermatitis remain unknown, at least in vitro. This study aimed to define how different statins affect MDC expression in HaCaT cells, a human keratinocyte cell line. EXPERIMENTAL APPROACH: To measure the effects of statins on MDC expression in HaCaT cells, we used a cell viability assay, reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay and Western blotting analyses. KEY RESULTS: Fluvastatin, but not atorvastatin or simvastatin, inhibited MDC expression induced by interferon (IFN)-gamma and NF-kappaB activation. A NF-kappaB inhibitor, but not a STAT1 inhibitor, suppressed MDC expression in HaCaT cells. Further, inhibition of p38 mitogen-activated protein kinases (MAPKs) significantly suppressed IFN-gamma-induced MDC expression and NF-kappaB activation. Interestingly, fluvastatin suppressed IFN-gamma-induced NF-kappaB activation in parallel with p38 MAPK phosphorylation. CONCLUSIONS AND IMPLICATIONS: These results indicate that fluvastatin inhibited expression of the CC chemokine MDC induced by IFN-gamma in HaCaT cells, by inhibiting NF-kappaB activation via the p38 MAPK pathway. This blockade of a Th2 chemokine by fluvastatin may suppress the infiltration of Th2 cells into skin lesions and lessen the skin inflammation seen in atopic dermatitis, suggesting a potential therapeutic use of fluvastatin for this condition.

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5: Clinical cancer research : an official journal of the American Association for Cancer Research, 2009 Apr 1, 15(7)
CCL22 recruits CD4-positive CD25-positive regulatory T cells into malignant pleural effusion.

[Abstract]PURPOSE: The aim of this study was to explore the presence of the chemokines CCL22 and CCL17 in malignant pleural effusion, and the chemoattractant activity of these chemokines on CD4-positive CD25-positive Foxp3-positive regulatory T cells infiltrating into the pleural space. EXPERIMENTAL DESIGN: The concentrations of CCL22 and CCL17 in both pleural effusions and sera from 33 patients with lung cancer were determined. Flow cytometry was done to determine T lymphocyte subsets in cell pellets of pleural effusion. Pleural cells were analyzed for the expression of CCL22 and CCL17. The chemoattractant activity of CCL22 for regulatory T cells in vitro and in vivo was also observed. RESULTS: The concentration of CCL22 in malignant pleural effusion was significantly higher than that in the corresponding serum. Pleural fluid from lung cancer patients was chemotactic for regulatory T cells, and this activity was partly blocked by an anti-CCL22, but not by an anti-CCL17 antibody. Intrapleural administration of CCL22 of patients produced a marked progressive influx of regulatory T cells into pleural space. CONCLUSIONS: Compared with serum, CCL22 seemed to be increased in malignant pleural effusion, and could directly induce regulatory T cell infiltration into the pleural space in patients with malignant effusion.

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6: Cancer, 2009 Jun 1, 115(11)
Genetic polymorphism in chemokine CCL22 and susceptibility to Helicobacter pylori infection-related gastric carcinoma.

[Abstract]BACKGROUND: Gastric carcinoma is widely considered to be related to Helicobacter pylori infection, and the chemokine (C-C motif) ligand 22 (CCL22) plays an important role in suppressing immune responses against H. pylori and tumor cells. In this study, the authors examined the association between single nucleotide polymorphisms (SNPs) in the CCL22 gene and the risk of gastric carcinoma. METHODS: Information on SNPs in the CCL22 coding region was obtained from the HapMap Project database. Genotypes were determined in a case-control cohort that consisted of 1001 patients with gastric carcinoma and 1066 controls, and odds ratios (ORs) and 95% confidence intervals (95% CIs) were computed by using a logistic regression model. Serum H. pylori antibody levels were measured by using an enzyme-linked immunosorbent assay. RESULTS: The 16C-->A SNP (reference SNP no. 4359426) in exon 1 of the CCL22 gene, which causes a 2 aspartate (2Asp) to 2 alanine (2Ala) substitution in the CCL22 protein, was associated with a significantly increased risk of gastric carcinoma. Individuals who were homozygous for the Ala/Ala genotype had an OR of 2.27 (95% CI, 1.28-4.02) compared with individuals who had the Asp/Asp genotype. Stratification analysis indicated that the association was more pronounced among men (OR, 2.64; 95% CI, 1.29-5.41) and among younger individuals (OR, 2.85; 95% CI, 1.36-5.96) compared with women and older individuals. Moreover, a multiplicative joint effect between the CCL22 SNP and H. pylori infection that intensified the risk was observed (OR for the presence of both Ala/Ala genotype and H. pylori infection, 18.37; 95% CI, 2.30-146.67). CONCLUSIONS: The results from this study suggested that the CCL22 polymorphism is associated with an increase risk of developing H. pylori infection-related gastric carcinoma.

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7: Cancer research, 2009 Feb 24,
Regulatory T Cells Recruited through CCL22/CCR4 Are Selectively Activated in Lymphoid Infiltrates Surrounding Primary Breast Tumors and Lead to an Adverse Clinical Outcome.

[Abstract]Immunohistochemical analysis of FOXP3 in primary breast tumors showed that a high number of tumor-infiltrating regulatory T cells (Ti-Treg) within lymphoid infiltrates surrounding the tumor was predictive of relapse and death, in contrast to those present within the tumor bed. Ex vivo analysis showed that these tumor-infiltrating FOXP3(+) T cells are typical Treg based on their CD4(+)CD25(high)CD127(low)FOXP3(+) phenotype, their anergic state on in vitro stimulation, and their suppressive functions. These Ti-Treg could be selectively recruited through CCR4 as illustrated by (a) selective blood Treg CCR4 expression and migration to CCR4 ligands, (b) CCR4 down-regulation on Ti-Treg, and (c) correlation between Ti-Treg in lymphoid infiltrates and intratumoral CCL22 expression. Importantly, in contrast to other T cells, Ti-Treg are selectively activated locally and proliferate in situ, showing T-cell receptor engagement and suggesting specific recognition of tumor-associated antigens (TAA). Immunohistochemical stainings for ICOS, Ki67, and DC-LAMP show that Ti-Treg were close to mature DC-LAMP(+) dendritic cells (DC) in lymphoid infiltrates but not in tumor bed and were activated and proliferating. Furthermore, proximity between Ti-Treg, CD3(+), and CD8(+) T cells was documented within lymphoid infiltrates. Altogether, these results show that Treg are selectively recruited within lymphoid infiltrates and activated by mature DC likely through TAA presentation, resulting in the prevention of effector T-cell activation, immune escape, and ultimately tumor progression. This study sheds new light on Treg physiology and validates CCR4/CCL22 and ICOS as therapeutic targets in breast tumors, which represent a major health problem. [Cancer Res 2009;69(5):2000-9].

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8: Journal of immunology (Baltimore, Md. : 1950), 2009 Mar 1, 182(5)
NK-dependent increases in CCL22 secretion selectively recruits regulatory T cells to the tumor microenvironment.

[Abstract]Tumor-induced immune suppression involves the accumulation of immune-suppressive infiltrates in the microenvironment. This study demonstrates increased numbers of CD4(+)CD25(+)FoxP3(+) regulatory T cells (Tregs) in the lungs of C57BL/6 mice bearing a metastatic Lewis lung carcinoma (LLC) variant. These Tregs suppressed the proliferation of endogenous CD4(+)CD25(-) cells and expressed higher levels of the chemokine receptor CCR4 than other types of T cells. LLC-bearing lungs secreted elevated levels of the CCR4-associated chemokine CCL22 compared with normal lungs. However, CCL22 was not secreted by LLC or normal epithelial controls, suggesting that CCL22 is secreted by a nonepithelial component of the microenvironment. Migration assays revealed that medium conditioned by LLC-bearing lungs selectively recruited Tregs at higher frequencies than did medium conditioned by normal lungs. Neutralization of CCL22 significantly reduced this selective recruitment toward both conditioned media. A series of immunomagnetic isolations, FACS, and flow cytometric analyses were used to isolate different cellular fractions from both normal and LLC-bearing lungs. When isolated, only the NK-containing fractions secreted CCL22, and the same fraction isolated from LLC-bearing lungs secreted higher levels. Depletion of NK cells from both normal and LLC-bearing lung tissue significantly reduced CCL22 secretion, suggesting that a large portion of secreted CCL22 is NK cell dependent. Flow cytometric analysis of the lung NK compartments revealed no significant increase in NK cell numbers across LLC-bearing lung tissue as a whole as compared with normal tissue. However, immunofluorescent staining revealed an increased frequency of NK cells at the tumor periphery that were closely associated with the elevated FoxP3(+) infiltrate.

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9: Journal of biomedical materials research. Part A, 2009 Feb 9, 182(5)
Titanium induced production of chemokines CCL17/TARC and CCL22/MDC in human osteoclasts and osteoblasts.

[Abstract]There is increasing evidence that titanium (Ti(IV)) ions are released from orthopedic implants and play a role in aseptic loosening. This study aimed to investigate whether titanium induces expression of chemokines and cytokines that are important in osteoclastogenesis in human osteoclasts and osteoblasts. Incubation of those cells with 1 muM Ti(IV) significantly upregulated expression of CCL17/TARC and CCL22/MDC, RANK-L, M-CSF and pro-inflammatory cytokines as determined by quantitative real-time PCR and ELISA assays. Additionally, flow cytometry was used to show Ti(IV) related increased expression of CCR4, the cognate receptor for CCL17 and CCL22 in challenged osteoclast precursors. These results strongly suggest that Ti(IV) ions play a role in the recruitment of osteoclast precursors to the bone-implant interface by increasing CCL17 and CCL22 expression and by upregulating their cognate receptor. Moreover the increased expression of RANK-L and M-CSF by osteoblasts together with increased levels of pro-inflammatory cytokines may enhance osteoclast differentiation and activity, and subsequently contribute to the pathomechanism of aseptic loosening. (c) 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2009.

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10: Journal of immunology (Baltimore, Md. : 1950), 2008 Oct 15, 181(8)
Overproduction of IgE induces macrophage-derived chemokine (CCL22) secretion from basophils.

[Abstract]Macrophage-derived chemokine (MDC) CCL22 is a potent chemoattractant for Th2 cells and has been implicated in Th2-predominant allergic inflammation. In the present study, we demonstrated that basophils produce MDC in response to monomeric IgE. In trinitrophenyl (TNP)-IgE transgenic mice, serum levels of MDC were persistently higher than in wild-type mice. The i.v. administration of TNP-specific IgE to wild-type mice transiently induced an elevation in serum MDC, which appeared to be mediated by Fc epsilonRI, as no increase in serum MDC was observed after IgE administration in FcRgamma (-/-) mice. However, the IgE-mediated increase in MDC was observed in mast cell-deficient mice. Freshly isolated bone marrow cells and bone marrow-derived basophils secreted MDC in response to TNP-IgE without Ag stimulation. Furthermore, MDC production was not observed in bone marrow-derived basophils isolated from FcRgamma (-/-) mice. IgE activated Lyn and ERK 1/2 in bone marrow-derived basophils. Treatment of TNP-IgE transgenic mice with a basophil-depletion Ab (Ba103) resulted in decreased serum MDC levels. Thus, IgE appears to be capable of stimulating basophils to produce MDC in the absence of a specific Ag, which may contribute to IgE-mediated and/or Th2-predominant allergic inflammation.

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11: Journal of interferon & cytokine research : the official journal of the International Society for Interferon and Cytokine Research, 2008 May, 28(5)
In vitro induction of a dendritic cell phenotype in primary human acute myelogenous leukemia (AML) blasts alters the chemokine release profile and increases the levels of T cell chemotactic CCL17 and CCL22.

[Abstract]Immunotherapy is now considered in acute myelogenous leukemia (AML). A dendritic cell (DC) phenotype can be induced in primary human AML cells by in vitro culture in the presence of various cytokine combinations. The aim was to investigate whether this phenotypic alteration is associated with altered chemokine release. AML cells were cultured according to four protocols that have been characterized in detail for AML-DC induction: (1) granulocyte-macrophage colony-stimulating factor (GM-CSF) + interleukin-4 (IL-4) days 1-14 and tumor necrosis factor-alpha (TNF-alpha) for days 6-14, (2) GM-CSF + IL-4 + TNF-alpha + FMS-like tyrosine kinase 3-ligand (Fl3-L) for 8 days, (3) GM-CSF + IL-4 + TNF-alpha + Flt3-L + stem cell factor (SCF) + transforming growth factor-beta1 (TGF-beta1) for 8 days, and (4) 25 Gy gamma-irradiation combined with culture in the presence of GM-CSF + SCF + IL-3 for 4 days. Significantly increased AML-DC release of CCL17 and CCL22 was observed for protocols 1, 2, and 3, whereas effects on CCL2-5, CXCL8, and CXCL10 differed in all protocols. Neutralization studies using a transwell migration assay demonstrated the increased level of CCL17 and CCL22 release was important for AML-DC chemotaxis of normal T cells. Induction of a dendritic AML cell phenotype is associated with an altered chemokine release profile. Detailed characterization of chemokine release should be included in future studies of AML-DC vaccination.

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12: Multiple sclerosis (Houndmills, Basingstoke, England), 2008 May, 14(4)
MDC/CCL22 intrathecal levels in patients with multiple sclerosis.

[Abstract]MDC/CCL22 has been detected in the brain of mice with experimental autoimmune encephalomyelitis. MDC/CCL22 cerebrospinal fluid levels were evaluated in 56 patients with multiple sclerosis (MS) and in 17 controls. No significant differences were found, even when stratifying patients according to the disease subtype. Stratifying by gender, significantly increased MDC/CCL22 levels were observed in female patients when compared with female controls and male patients (109.03 versus 98.54 and 99.37 pg/mL, P = 0.034 and 0.018, respectively). Therefore, MDC/CCL22 is likely to play a role in the development of MS in females only, possibly influencing the intracerebral recruitment of Th2 cells, which produce anti-inflammatory cytokines.